How do I query between two dates using MySQL?

Question

The following query:

SELECT * FROM `objects` 
WHERE (date_field BETWEEN \'2010-09-29 10:15:55\' AND \'2010-01-30 14:15:55\')

returns nothin

Answer 1

As extension to the answer from @sabin and a hint if one wants to compare the date part only (without the time):

If the field to compare is from type datetime and only dates are specified for comparison, then these dates are internally converted to datetime values. This means that the following query

SELECT * FROM `objects` WHERE (date_time_field BETWEEN '2010-01-30' AND '2010-09-29')

will be converted to

SELECT * FROM `objects` WHERE (date_time_field BETWEEN '2010-01-30 00:00:00' AND '2010-09-29 00:00:00')

internally.

This in turn leads to a result that does not include the objects from 2010-09-29 with a time value greater than 00:00:00!

Thus, if all objects with date 2010-09-29 should be included too, the field to compare has to be converted to a date:

SELECT * FROM `objects` WHERE (DATE(date_time_field) BETWEEN '2010-01-30' AND '2010-09-29')